Problem!!!

**Wild Dingo** · 13th January 2007, 12:14 PM

Awhile back I made a round table from OLD Jarrah boards and had some problems with the ends turning up... I resolved this issue by putting in some serious boards on the underside glued and screwed to the top... so along with those two there was a centre peice and the two leg supports across the bottom of the table

A problem has now occured

As can be seen the base was pretty much covered with the boards in the first shot... the design actually only called for the single thin one in the middle which I ended up beefing up!

so given the wood was DRY as... been outside on the side of the humpyhoochy for over 8 years
It was biscuit joined and glued along the edges
It started coming apart on the small end peices and now every board has begun to pull open the centre peices seeming to be worse

When I finished it I varnished both sides first to counteract any movement caused by having varnish on one side only then varnished the hell out of the top

So cureall if you please gents!!

Do I bring it back to the cave and pull it apart and do SOMETHING to it to stop this
do I use dowels instead of the buscuits? I can make whatever size dowel you think it needs
Or can you think of something Im missing here? I repeat the wood was dry

Mind you her house gets hot as hell during the day... perhaps I should have stored it there before I made it? shyte! then Id have to have lugged the sodding tools over to her tiny place and built it there... nah that cant be bloody right! It shouldnt have done this!

No I dont have nor can I afford a flamin domino thingy so please dont suggest it

**scottyk** · 13th January 2007, 02:33 PM

What sort of glue was originally used?
If you can get all the boards apart and reglue them using WEST or simalr epoxy, never lets go!
Jarrah is a bugger for doing that though, seems to move alot.
Let us know what you decide to do.
Scotty

**echnidna** · 13th January 2007, 02:38 PM

The only cure is to rebuild it. Once the timber is stabilized.

Dowels , biscuits or nothing are all equal in strength

If you ran a spline almost to each end and glued a loose tongue in the end result may be slightly stronger, but I wouldn,t waste me time doin that

**old_picker** · 13th January 2007, 04:03 PM

Moisture escaping has caused this IMHO. I would recomend storing timber for 6 to 12 months before using it allowing a good acclimatisation. Also dont leave the job in a hot shed on 35deg + day

**Ianab** · 13th January 2007, 04:32 PM

Looks like a classic crossgrain join / movement sort of problem.

There are several ways of doing it, but you HAVE to let the top expand and contract with the seasons. Even though the wood was properly dry it's still going to gain and loose water depending on the season, and it WILL move.

I would suggest taking it apart and rebuilding it, but slot the holes in the cross pieces so they can slide with seasonal movement. They will still work to keep the top flat but wont completely restrict it's movement. Stronger glue wont help, even if the glue doesn't fail the wood itself will eventually split.

Cheers

Ian

**Zsteve** · 13th January 2007, 04:36 PM

Sounds and looks like the timber is drying out and shrinking in your hot house - hence the gaps. Timber constantly changes with temperature/humidity and a change in environment where it is kept even if it is old timber will usually result in a change.

You could rejoin the boards by any of the methods suggested but instead of screwing it underneath secure it with ''buttons'' that are screwed only to the table top but have a tongue that fits into a groove in your cross members(table top support frame), this allows for a sliding movment as the timber expands and contracts.

regards
Steve

**Wild Dingo** · 13th January 2007, 08:16 PM

Okay cheers I figured Id have to bring it back and take it apart to reset it... okay so now I take it apart and what? run a spline through edge of each board? shape a circular rim to go underneath the tops similar to a normal rectangle top (the rails?) and put them button things all round? will that stop the boards moving so much?

I also had a feeling it would have something to do with their house bein so hot... damnit!

cheers

**ozwinner** · 13th January 2007, 08:24 PM

I think it was caused by the boards being restrained by the screws.

If you had allowed for the movement of the timber through buttons, or slots as I use, you prolly wouldnt see the cracks as the whole top could move as one rather than a collection of separately restrained pieces of timber.

Al

**Ianab** · 13th January 2007, 09:20 PM

will that stop the boards moving so much?

Dont try and stop the boards moving, in width anyway. The forces that the wood develops are enough to tear any join, or the wood itself apart. You have to redesign so that the table top CAN move. That way if the table decides to shrink 5mm in width, it can. Next month it may be humid and it could GROW 5mm.
Glue it up again and mount it with some sort of sliding fixture and all will be well.

Cheers

Ian

**Harry72** · 13th January 2007, 10:21 PM

Yep rip it apart rejoint the boards now they've climatised glue them back up and allow for movement, I dont think there's any need for biscuits or dowels.

Did you allow them to climatise for a week or two when you initially machined the wood?

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